Method and apparatus for three-dimensional surface morphometry

ABSTRACT

The present invention provides a method and apparatus for non-contacting morphomtry of three-dimensional surface of an object such as a human body in a shorter time period and with higher precision, wherein the present non-contacting morphometry of three-dimensional surface of an object involves a plurality of measuring video heads, A i , B i , C i  and D i  and a controlling unit for controlling the measuring time of the measuring heads and for processing and storing the obtained data from the measurements. The present method comprises the steps of: placing the object to be measured so that one axis thereof lies along and with an imaginary central axis; placing the object to be measured so that the measuring heads are arranged on each of n (n≧1) planes intersecting the imaginary central axis where the optical axis of each measuring head faces the imaginary central axis and each annular slice of the surface of the object is covered by the sight fields of the m (m≧3) measuring heads; operating simultaneously one group of a plurality of measuring video heads, the sight field of each of which does not substantially overlap with the sight field of the other in the group, and thereafter, operating other group of a plurality of measuring video heads, the sight field of each of which does not substantially overlap with the sight field of the other in the group. The n×m sets of data thus obtained in the foregoing steps are processed to obtain three-dimensional data.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a method and apparatus formorphometry of three-dimensional surface of an object such as a humanbody with higher precision and efficiency.

[0002] As for an apparatus of morphometry of three-dimensional surfaceof an object such as a human body, among medical and apparel fields,there is a strong need to measure efficiently with a required precision.However, in order to utilize as data such a complex form as a humanbody, the whole body must be entirely scanned and the body must bestanding still during the measurement, and thus, under a such acondition, it is a prerequisite that the measuring apparatus must beable to measure as fast as possible. As for the morphometry of thesurface of a still object, there have been a number of proposals so far,and there has been proposed a morphometry of three-dimensional surfaceof an object such as a human body. In the Japanese Patent Laid-OpenPublication No. Hei10-122850, there is disclosed an apparatus ofthree-dimensional morphometry using PSD. The disclosed apparatus has acomplex mechanism, requiring a moving frame, a plurality of sensorsdisposed facing each other on each of the two opposite side walls of theframe for scanning and operating light beams horizontally for measuringthe distance to the human body, and a driving mechanism for moving theframe. In addition, it is considered to be difficult to have somemeasuring time short enough for avoiding the effect of movement causedby the movement due to the physiological need of a human body.

SUMMARY OF THE INVENTION

[0003] In the present invention, the following requirement goals wereset for the present morphometry of a human body:

[0004] 1. measuring range (height): 900 mm to 2,000 mm;

[0005] 2. measuring range (diameter): 600 mm to 1,500 mm

[0006] 3. measuring time (entire body): 1 second;

[0007] 4. acceptable tolerance of measured value (absolute tolerance): 1mm (preferably, 0.2 mm);

[0008] 5. processing time of the measured data: 30 second.

[0009] One of the objects of the present invention is to provide amethod and apparatus that enables to solve each of the above problems,wherein the method and apparatus measures a three-dimensional surface ofan object, such as a human body, with higher precision and efficiency.

[0010] To achieve the object and in accordance with the purpose of theinvention, as embodied and broadly described herein, the presentinvention comprises a method of three-dimensional morphometry ofnon-contact type having a plurality of measuring video heads disposedfacing the object to be measured and a controlling unit for controllingthe measuring time period for each of the measuring video heads and forprocessing and storing the measured data, and the method furthercomprising the steps of placing in a space the object to be measured sothat one axis of the object to be measured [thereof] lies along and withan imaginary central axis of the space; placing the object to bemeasured so that the measuring heads are arranged on each of n (n≧1)planes intersecting the imaginary central axis where the optical axis ofeach measuring head lies on one of the n planes and is substantiallyperpendicular to [faces] the imaginary central axis and faces eachannular slice of the surface of the object is covered by the sightfields of the m (m≧3) measuring heads; operating simultaneously onegroup of a plurality of measuring video heads, the sight field of eachof which does not substantially overlap with the sight field of theother in the group, and thereafter, operating other group of a pluralityof measuring video heads, the sight field of each of which does notsubstantially overlap with the sight field of the other in the group;and processing the n×m sets of data obtained in the foregoing steps andthereby to obtain three-dimensional data.

[0011] The present invention also provides an apparatus embodying theforegoing method of three-dimensional morphometry, the apparatuscomprising: a space for placing an object to be measured so that oneaxis of the object [thereof] lies along and with an imaginary centralaxis of the space; a plurality of measuring heads being disposed outsideof the space for each to capture an image of a portion of a surface ofthe object while the portion of surface may substantially overlap witheach other; and a controlling unit for obtaining three-dimensional databy operating a group of a plurality of measuring heads, the sight filedof each of which does not substantially overlap with that of othermeasuring heads in the group, and thereafter, operating other group of aplurality of measuring heads, the sight field of each of which does notsubstantially overlap with that of other measuring heads in the group,and thereby processing a plurality of sets of data obtained by theoperations.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings, which are incorporated herein andconstitute a part of this specification for only an illustrativepurpose, illustrate an embodiment of the invention and, together withthe description, serve to explain the objects, advantages and principlesof the invention. In the drawings,

[0013]FIG. 1 is a schematic perspective view illustrating the principleof the method and apparatus of the morphometry of three dimensionalsurface of an object in accordance with the present invention;

[0014]FIG. 2 is a schematic plan view illustrating the relationshipbetween the overlap of sight fields of cameras and the object to bemeasured;

[0015]FIG. 3 is a schematic diagram illustrating the arrangement ofmeasuring heads and the operational principle of the operation of theoptics;

[0016]FIG. 4 is another schematic diagram illustrating the arrangementof measuring heads and the projecting pattern.

[0017]FIG. 5 is a perspective view illustrating the arrangement ofmeasuring heads with respect to the image capturing frame in anembodiment of the method and apparatus of morphometry of threedimensional surface in accordance with the present invention;

[0018]FIG. 6 is a schematic diagram illustrating the arrangement ofvideo heads for measurement used in the apparatus in accordance with thepresent invention along in the vertical direction and the overlap ofsight fields;

[0019]FIG. 7 is a schematic block diagram illustrating an exemplarysystem of the apparatus of morphometry in accordance with the presentinvention;

[0020]FIG. 8 illustrates a sequence of measurements, data transfer, anddata processing of the embodiment of the morphometry apparatus inaccordance with the present invention; and

[0021]FIG. 9 illustrates a flowchart of measurements, data transfer, anddata processing of the embodiment of the morphometry apparatus inaccordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] A detailed description of one preferred embodiment according tothe present invention will now be given with reference to theaccompanying drawings.

[0023] Now referring to FIG. 1, there is shown a schematic perspectivediagram illustrating the principle of the method and apparatus ofmorphometry of three-dimensional surface of an object in accordance withthe present invention. In FIG. 5, there is shown a perspective diagramof the arrangement of measuring heads with respect to an image capturingframe in the embodiment of the method and apparatus of morphometry ofthree-dimensional surface of an object in accordance with the presentinvention. The schematic diagram of FIG. 1 illustrates an arrangementwhere an object (Ob) 2, such as a standing human body, is placed on abase 3 of an image capturing frame shown in FIG. 5, with an imaginarycentral axis (IA) 1 being in the center thereof, with respect to CCDcameras of a given level.

[0024] CCD cameras, 4 _(Ai), 4 _(Bi), 4 _(Ci), 4 _(Di), each is arrangedsuch that each optical axis lies on the plane P_(i) which intersects theimaginary central axis (IA) of FIG. 1 and the sight fields of four CCDmeasuring heads cover whole annular slice of the object (Ob) 2. FIG. 2illustrates a plan view showing the overlapping sight fields of eachcamera 4 _(Ai), 4 _(Bi), 4 _(Ci), 4 _(Di) and their relationship betweenthe object to be measured (Ob).

[0025]FIG. 3 shows the arrangement of the measuring head and thefunctional principle of the operation of optical components. FIG. 4 isanother schematic diagram of the arrangement of the measuring head andthe image capturing pattern. The measuring heads A_(i), B_(i), C_(i),D_(i) each incorporates a CCD camera 4, a polygon mirror 5, a laserlight source 6 and a cylindrical lens 7. The CCD camera 4 and thepolygon mirror 5 are placed at a predetermined distance (at a base linedistance) from each other. The light beam emitted from the laser 6,which is a time-domain modulated light source, is focused on the polygonmirror 5 by the cylindrical lens 7 to be scanned by the rotation of thepolygon mirror 5 and thereby forming on the object Ob a moiré patterncorresponding to the surface configuration of the object Ob. The patternis captured by the CCD camera 4.

[0026]FIG. 6 is a schematic diagram illustrating the arrangement, alongthe direction of height, of the measuring video heads used in theembodiment apparatus of the present invention and the overlaps of sightfields. In FIG. 6, only the measuring heads A₂, A₃, A₄ of FIG. 5 areshown for simplicity. For example, the measuring head A₃ captures theimage of the surface of the object (not shown) scanned by the polygonmirror 5 _(A3).

[0027]FIG. 7 is a system block diagram of an embodiment apparatus of thepresent apparatus of morphometry of three-dimensional surface. In thisembodiment, a total of 16 heads are used with 4 heads on each of the 4rows. The measuring heads A₁, A₂, A₃, A₄ are arranged in a line as shownin FIG. 5. Other measuring heads B₁ through B₄, C₁ through C₄, D₁through D₄ are also arranged in a similar manner. A controlling PC (I)11 and a controlling PC (II) 12 each processes the output from themeasuring heads to be controlled in the raw A and B, and a controllingPC (III) 13 and a controlling PC (IV) 14 each processes the output fromthe measuring heads to be controlled in raw C and D. The output datafrom each of the controlling PCs 11 through 14 are processed by a dataprocessing personal computer 18. The data after being processed aredelivered to an external computer via a hub 17.

[0028]FIG. 8 is a sequence chart of the measurement, data transfer, dataprocessing in the embodiment of the present apparatus of morphometry ofthree-dimensional surface of an object. In the system according to thepresent embodiment, 2.0 seconds are set for the scheduled measuring timeperiod for capturing data and preprocessing data, 2.0 seconds for thedata transfer and 60 seconds for the integration of data. During thefirst 0.5 seconds, each of the measuring heads A₁, A₃, C₁ and C₃ isoperated. During this time period, all of the measuring heads A₂, A₄,C₂, C₄, B₁, B₂, B₃, B₄, D₁, D₂, D₃, and D₄ each of which has anoverlapping sight field with one of the foregoing measuring heads arenot operated.

[0029] During the next 0.5 seconds (within 0.5 to 1.0 seconds), each ofthe measuring heads A₂, A₄, C₂ and C₄ is operated. During this period,all of the measuring heads A₁, A₃, C₁, C₃, B₁, B₂, B₃, B₄, D₁, D₂, D₃,and D₄ each of which has an overlapping sight field with one of theforegoing measuring heads are not operated. During the next 0.5 seconds(within 1.0 to 1.5 seconds), each of the measuring heads B₁, B₃, D₁ andD₃ is operated. During this time period, all of the measuring heads B₂,B₁, D₂, D₄, A₁, A₂, A₃, A₄, C₁, C₂, C₃, and C₄ each of which has anoverlapping sight field with one of the foregoing measuring heads arenot operated.

[0030] During the next 0.5 seconds (within 1.5 to 2 seconds), each ofthe measuring heads B₂, B₄, D₂ and D₄ is operated. During this timeperiod, all of the measuring heads B1, B3, D1, D3, A1, A2, A3, A4, C1,C2, C3, and C4 each of which has an overlapping sight field with one ofthe foregoing measuring heads are not operated. Then, each of A₂, A₄, C₂and C₄ is operated. During this time period, all of the measuring headsA₁, A₃, C₁, C₃, B₁, B₂, B₃, B₄, D₁, D₂, D₃, and D₄ each of which has anoverlapping sight field with one of the foregoing measuring heads arenot operated. The data thus obtained are then subjected to apreprocessing (i.e. noise elimination and filtering) in the controllingPCs (I, II, III, IV) 11, 12, 13, 14 to be finally transferred to dataprocessing personal computer 18. The data transfer is performed by usingTCP/IP protocols. In the data processing personal computer 18, thecomputation of coordinates and the data integration processing areperformed.

[0031]FIG. 9 shows a flow chart of the measurement, data transfer, dataprocessing in the embodiment of the apparatus of morphometry ofthree-dimensional surface of an object of the present invention. Theflow chart illustrates the flow of process starting with the measurementup to the outputting of final output data file.

[0032] The flow of process in the present data processing personalcomputer (hereinafter, “data processing PC”) is as follows: (step 20)the data processing PC directs the controlling personal computer(hereinafter, “controlling PC”) to start the measurement.

[0033] The flow of process in the present controlling PC is as follows:

[0034] (step 30) the controlling PC instructs the measuring head tostart the measurement.

[0035] (step 31) the controlling PC performs the preprocessing, such asfiltering, on the data captured by the measuring head.

[0036] (step 32) the controlling PC outputs and delivers thepreprocessed data output to the data processing PC.

[0037] The flow of process in the data processing PC is as follows:

[0038] (step 21) the data processing PC receives the preprocessed datafrom the controlling PC.

[0039] (step 22) the data processing PC performs transformationoperation on the data at each point belonging to a group.

[0040] (step 23) the data processing PC performs rotation andtranslation operation on the data at each point.

[0041] (step 24) the data processing PC performs integration andsmoothing operation on the data.

[0042] (step 25) the data processing PC outputs a data file comprisingcontour line data.

[0043] As can be seen from the description above, the method andapparatus of morphometry of three-dimensional surface of an object inaccordance with the present invention makes it possible to obtain thethree-dimensional data and the like of a human body within a very shorttime period of 2.0 seconds. And the data thus obtained can betransformed to represent in a three-dimensional representation and thento be immediately outputted. It should be appreciated by those skilledin the art that the disclosed embodiment provides a complete set ofsolutions for the quantitative problems and objects cited above. Thepresent invention made it possible to build a database ofthree-dimensional data of a human body by accumulating thus obtaineddata. The present invention also allows the use of personal database.However, it should be understood that the present invention is not to belimited to the description and embodiments described above and may bemodified within the scope of the technical concept described above aswell as the accompanying claims.

1. A method of non-contacting morphometry of three-dimensional surfaceof an object having a plurality of measuring video heads disposed facingthe object to be measured and a controlling unit for controlling themeasuring time period for each of the measuring video heads and forprocessing and storing the measured data, comprising the steps of:placing the object to be measured so that one axis thereof lies alongand with an imaginary central axis; placing the object to be measured sothat the measuring heads are arranged on each of n (n≧1) planesintersecting the imaginary central axis where the optical axis of eachmeasuring head faces the imaginary central axis and each annular sliceof the surface of the object is covered by the sight fields of the m(m≧3) measuring heads; operating simultaneously one group of a pluralityof measuring video heads, the sight field of each of which does notsubstantially overlap with the sight field of the other in the group,and thereafter, operating other group of a plurality of measuring videoheads, the sight field of each of which does not substantially overlapwith the sight field of the other in the group; and processing the n×msets of data obtained in the foregoing steps and thereby to obtainthree-dimensional data.
 2. An apparatus of morphometry ofthree-dimensional surface of an object, comprising: a space for placingan object to be measured so that one axis thereof lies along animaginary central axis; a plurality of measuring heads being disposedoutside of the space for each to capture an image of a portion of asurface of the object while the portion may overlap with each other; anda controlling unit for obtaining three-dimensional data by operating agroup of a plurality of measuring heads, the sight filed of each ofwhich does not substantially overlap with that of other measuring headsin the group, and thereafter, operating other group of a plurality ofmeasuring heads, the sight field of each of which does not substantiallyoverlap with that of other measuring heads in the group, and therebyprocessing a plurality of sets of data obtained by the operations.